Overload release clutch



April 26, 1955 R. w. BAILEY ETAL OVERLOAD RELEASE CLUTCH 3 Sheets-Sheet 1 Filed Aug. 17, 1954 0" a B o 1/ 3 J L IHW- bmv 77/0005 FAVLL W W A r Rr/m R. w. BAILEY ETAL 2,707,039- OVERLOAD RELEASE CLUTCH 3 Sheets-Sheet 2 ENT 84 I w W. I. 3 z 3 u A a 5 J 5 7 /M K 5- 7 6 n r \\-\x k/ April 26, 1955 Filed Aug. 17, 1954 April 1955 R. w. BAILEY ETAL 2,707,039

I OVERLOAD RELEASE CLUTCH Filed Aug. 17, 1954 3 s t s 3 TOR-9,. Ame-y.

W65 Paul R0 do United States Patent 2,707,039 OVERLOAD RELEASE CLUTCH Roy W. Bailey and John T. Faull, Detroit, Mich., assignors to Detroit Power Screwdriver Company, Detroit, Micl1., a corporation of Michigan Application August 17, 1954, Serial No. 450,495 8 Claims. (Cl. 192-56) is herein described illustratively with reference to the driving of a screw.

Various types of torque clutches are known, and each has been found objectionable e pressure required to depress the cam structure to the non-drive relation is determined by adjustment of the supporting spring. The cam action against spring pressure commences only when the work piece has stopped turning, and thus the tightness of the work piece is related to the adjusted pressure of the spring.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings in which V Figure 1 is a vertical section of the device in the idle position before driving;

Figures 2 and 3 are sections on the lines 22 and of the device in the 2,707,039 Patented Apr. 26, 1955 sponding to Figure 1, and Figures 7 and 8 are sections on the lines 7--7 and 88 of Figure 1.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

igure 1 is shown a fixed cylindrical housing 1 in does not slide. An upper spindle 4 passes downwardly through the member 2 means are provided for spaced from the lower extremity of the spindle 4 by a radial ball bearing 5 engaging a surrounding part as will be described. The pin 5 is held in the spindle 4 by a cross pin 8 which also passes through a surrounding bushing 9.

From the bearing 7 is suspended a retaining sleeve 10 having its upper end spaced at retainer 15 which rests on the shoulder 16 near the lower end of the member 14. Th the clutch spindle 12 carries an adjustable nut 17 on which is mounted a coil spring 18 that supports the slidable clutch body 14 and retainer 15.

he upper end of the clutch body 14 is reduced in outside diameter at 20 to receive a cam sleeve 21 resting on the shoulder 14 thus formed. On the upper end of the sleeveZl are formed or provided a pair of cam elements 22 spaced apart. The pin 8 is projected the lower notches 42. However, there is no drive from the clutch comprising a retaining sleeve surrounding said body and spindle 12 to the lower spindle 44 until the pin 40 slidable therewith, said sleeve having an aperture adapted enters the slot 45. to receive and retain a projected portion of said locking The driving spindle 4 is next moved downwardly, while device, a fixed reset sleeve surrounding said retaining rotating, by any known or suitable means for this purmeans, the lower end of said reset sleeve having a flared pose, carrying with it the sleeve 15 and parts assembled inner surface engageable by said projected portion, therein. When this movement meets resistance by enwhereby to repel said locking device radially inward on gagement of the driver 50 with screwhead 51, further elevation of the first sleeve in the reset sleeve. downward movement of the assembly compresses the 4. A torque clutch as set forth in claim 1, further spring 18 and brings the pin 41 into the slot 45 to ro- 0 comprising a nut threaded on said body and constituting tate the lower spindle 44. The relative downward movethe retaining means for said spring, the tension of said ment of the clutch body 14 on the rollers 41 at this spring being adjustable by said nut. time is permitted by the upward play in the notches 42. 5. A torque clutch comprising a rotatable and verti- The same relative movement has brought the hole 35 of cally slidable drive spindle, a clutch spindle freely susclutch spindle 12 in a position to register with holes 30 15 pended therefrom, a clutch body slidably mounted on of clutch body 14, but the pins 36 cannot enter holes said clutch spindle, said clutch spindle havinga vertically 30 since the balls 31 are still retained or obstructed by elongated slot, a drive pin passing through said body and the sleeve 15. This is a position intermediate Figures 1 into said slot, a driven spindle slidably suspended from and 4. said clutch spindle, the upper end of said driven spindle When the screw 50 has been driven tight, the lower 20 having a notch directly below said slot and adapted to spindle 44 will stop rotating. At a resistance determined receive said drive pin on relative upward movement of by the pressure of spring 18, the rollers 23 will ride said driven spindle, a cam on the upper end of said clutch up on the cams 22 to depress the clutch body 14 until body, a driving member on said drive spindle and adapted the balls 31 register with and are projected into the holes to engage said cam radially to rotate said body, a spring 32 of sleeve 15. The clutch body 14 is thereby locked retained on said clutch spindle and bearing upwardly on in a position that holds the earns 22 entirely below the the lower end of said clutch body, a radial locking device rollers 23 so that the latter no longer drive the clutch in said clutch spindle and normally held idle therein, body and the lower spindle 44. Thus, on obtaining means at a higher level in said clutch body for interlockthe desired tightness of screw 51 as determined by the ing with said device on relative downward movement of pressure of spring 18, there is no further tightening of said body, said driving member being adapted to ride up the screw. on said cam and thereby depress said body to aline said The downward displacement of the clutch body 14 is interlocking means with said locking device on arrested shown by the gap 54 in Figure 4 over the inward shoulder rotation of said lower spindle, clutch spindle and clutch 55 of the clutch body which formerly engaged the head body.

of the clutch spindle 12. 35 6. A torque clutch comprising a rotatable and verti- The drive spindle 44 is now elevated, and the projected cally slidable drive spindle, a clutch spindle freely susballs 31 and ins 36 are pushed inward or reset by enpended therefrom, a clutch body slidably mounted on gagernent of the balls with a downwardly flared recess said clutch spindle, driving means joining said clutch 52 in the lower end of the reset sleeve 33. The assembly body to said clutch spindle, a driven spindle slidably susis now restored to the non-driving pOSl'tlOIl shown in pended from said clutch spindle, clutch means between Figure 1 and is ready for another operation as described. said driven spindle and said clutch body and adapted Although a specific embodiment of the invention has to engage on sliding movement of said clutch body, a cam been illustrated and described, it will be understood that. on the upper end of said clutch body, a driving member various alterations in the details of construction will be on said drive spindle and adapted to engage said cam made without departing from the scope of the invention radially to rotate said body, a spring retained on said as indicated by the appended claims. clutch spindle and bearing upwardly on the lower end What we claim is: of said clutch body, a radial spring-backed pin in said 1. A torque clutch comprising a rotatable and verticlutch spindle and normally held idle therein, said clutch cally slidable drive spindle, a clutch spindle freely susbody having an aperture at a higher level to receive pended therefrom, a clutch body slidably mounted on said pin on relative downward movement of said body, said clutch spindle, driving means joining said clutch body said driving member being adapted to slide up on said to said clutch spindle, a driven spindle slidably suspended cam and thereby depress said clutch body and to aline from said clutch spindle, clutch means between said said aperture with said pin on arrested rotation of said driven spindle and said clutch body and adapted to enlower spindle, clutch spindle and clutch body. gage on sliding movement of said clutch body, a cam on 7. A torque clutch as set forth in claim 6, further comthe upper end of said clutch body, a driving member on prising a rounded member freely movable in said apersaid drive spindle and adapted to engage said cam radially ture and engageable by said pin, a retaining sleeve surto rotate said body, a spring retained on said clutch rounding said body and slidable therewith, said sleeve spindle and bearing upwardly on the lower end of said having an aperture to receive and retain said rounded clutch body, a radial locking device in said clutch spindle member in a projected position out of the second aperand normally held idle therein, means at a higher level ture, a fixed reset sleeve surrounding said retaining in said clutch body for interlocking with said device on means, the lower end of said reset sleeve having a flared relative downward movement of said body, said driving inner surface engageable by said projected portion, member being adapted to ride up on said cam and therewhereby to repel said rounded member and pin radially by depress said body to aline said interlocking means inward on elevation of the first sleeve in the reset sleeve. with said locking device on arrested rotation of said 8. A torque clutch as set forth in claim 5, further lower spindle, clutch spindle and clutch body. comprising a nut threaded on said body and constituting 2. A torque clutch as set forth in claim 1, further the retaining means for said spring, the tension of said comprising retaining means at the outer wall of said spring being adjustable by said nut. body adapted to receive and retain projected portions of said locking deviciel, 211 fixed reisetf sleedve surrounding said References Cited in the file of this patent retaining means, t e ower en 0 sai reset sleeve having a flared inner surface engageable by said projected por- UNlTED STATES PATENTS tion, whereby to repel said locking device radially inward 998,615 Huneke July 25, 1911 on elevation of the first sleeve in the reset sleeve. 1,725,562 Borchert Aug. 20, 1929 3. A torque clutch as set forth in claim 1, further 2,263,709 Van Sittert Nov. 25, 1941 

